Assessor [Archived 05-31-2023] - Parcel Universe

A complete, historic universe of Cook County parcels with attached geographic, governmental, and spatial data.

When working with Parcel Index Numbers (PINs) make sure to zero-pad them to 14 digits. Some datasets may lose leading zeros for PINs when downloaded.

Additional notes:<ul><li>Data is attached via spatial join (st_contains) to each parcel's centroid.</li>
<li>Centroids are based on <a href="https://datacatalog.cookcountyil.gov/Property-Taxation/ccgisdata-Parcel-2021/77tz-riq7">Cook County parcel shapefiles</a>.</li>
<li>Older properties may be missing coordinates and thus also missing attached spatial data (usually they are missing a parcel boundary in the shapefile).</li>
<li>Newer properties may be missing a mailing or property address, as they need to be assigned one by the postal service.</li>
<li>Attached spatial data does NOT go all the way back to 1999. It is only available for more recent years, primarily those after 2012.</li>
<li>The universe contains data for the current tax year, which may not be complete or final. PINs can still be added and removed to the universe up until the Board of Review closes appeals.</li>
<li>Data will be updated monthly.</li>
<li>Rowcount and characteristics for a given year are final once the Assessor <a href="https://www.cookcountyassessor.com/assessment-calendar-and-deadlines">has certified the assessment roll</a> for all townships.</li>
<li>Depending on the time of year, some third-party and internal data will be missing for the most recent year. Assessments mailed this year represent values from last year, so this isn't an issue. By the time the Data Department models values for this year, those data will have populated.</li>
<li>Current property class codes, their levels of assessment, and descriptions can be found <a href="https://prodassets.cookcountyassessor.com/s3fs-public/form_documents/classcode.pdf">on the Assessor's website</a>. Note that class codes details can change across time.</li>
<li>Due to decrepencies between the systems used by the Assessor and Clerk's offices, <i>tax_district_code</i> is not currently up-to-date in this table.</li></ul>
For more information on the sourcing of attached data and the preparation of this dataset, see the <a href="https://gitlab.com/ccao-data-science---modeling/data-architecture">Assessor's data architecture repo</a> on GitLab.

<a href="https://datacatalog.cookcountyil.gov/stories/s/i22y-9sd2">Read about the Assessor's 2022 Open Data Refresh.</a>

一个包含库克县所有地块的完整、历史宇宙，附带地理、政府和空间数据。

在处理地块索引编号（PIN）时，请确保将它们零填充至14位数字。一些数据集在下载时可能会丢失PIN的前导零。

附加说明：<ul><li>数据通过空间连接（st_contains）附加到每个地块的重心。</li><li>重心基于<a href="https://datacatalog.cookcountyil.gov/Property-Taxation/ccgisdata-Parcel-2021/77tz-riq7">库克县地块形状文件</a>。</li><li>较旧的财产可能缺少坐标，因此也缺少附加的空间数据（通常在形状文件中缺少地块边界）。</li><li>较新的财产可能缺少邮寄或财产地址，因为它们需要由邮政服务分配。</li><li>附加的空间数据并非追溯到1999年，它仅适用于近年来的数据，主要是2012年之后的年份。</li><li>该宇宙包含当前税年的数据，这些数据可能不完整或最终确定。在审评委员会关闭上诉之前，PIN仍然可以添加到或从宇宙中删除。</li><li>数据将每月更新。</li><li>给定年份的行数和特征在评估员<a href="https://www.cookcountyassessor.com/assessment-calendar-and-deadlines">对所有镇的评估清单进行认证</a>后即为最终确定。</li><li>根据年份的不同，最近一年的一些第三方和内部数据可能缺失。今年邮寄的评估代表去年的价值，这不是问题。等到数据部门为本年建模价值时，这些数据将已填充。</li><li>当前财产类别代码、评估水平和描述可以在评估员的<a href="https://prodassets.cookcountyassessor.com/s3fs-public/form_documents/classcode.pdf">网站上找到</a>。请注意，类别代码的详细信息可能随时间而变化。</li><li>由于评估员办公室和书记办公室使用的系统之间存在差异，<i>tax_district_code</i>在此表中尚未更新。</li></ul>

有关附加数据的来源和此数据集的准备情况，请参阅GitLab上的评估员数据架构存储库<a href="https://gitlab.com/ccao-data-science---modeling/data-architecture">Assessor's data architecture repo</a>。</li><li>有关评估员2022年开放数据更新的更多信息，请参阅<a href="https://datacatalog.cookcountyil.gov/stories/s/i22y-9sd2">Assessor's 2022 Open Data Refresh</a>。</li>